An On-chip Chemiluminescent Immunoassay for Bacterial Detection using in Situ-synthesized Cadmium Sulfide Nanowires with
- PDF / 4,271,428 Bytes
- 11 Pages / 612 x 797 pts Page_size
- 68 Downloads / 207 Views
Original Article
An On-chip Chemiluminescent Immunoassay for Bacterial Detection using in Situ-synthesized Cadmium Sulfide Nanowires with Passivation Layers Hong-Rae Kim1, Ji-Hong Bong1, Jaeyong Jung1, Jeong Soo Sung1, Min-Jung Kang2, Jae-Gwan Park2 & Jae-Chul Pyun 1,* Received: 7 April, 2020 / Accepted: 28 May, 2020 / Published online: 27 August, 2020 â’¸The Korean BioChip Society and Springer 2020
Abstract The passivation layers of an in situ-synthesized cadmium sulfide (CdS) nanowire (NW) photosensor were prepared for two reasons: (1) to improve the physical stability of the NW on an interdigitated electrode and (2) to enhance the immobilization efficiency of proteins for the on-chip immunoassay. The passivation layer was estimated to have suitable optical properties, and the photoresponse of photosensor was increased after the formation of passivation layer. The immobilization efficiency of a parylene-H film through covalent bonding was compared with the immobilization of Z-domains through physical adsorption. Finally, on-chip chemiluminescent immunoassay of bacteria was carried out by immobilizing antibodies against Escherichia coli through Z-domains for the orientation control of antibodies. The limit of detection was determined to be less than 104 E. coli/mL (n=3), and the sensitivity of bacterial detection was estimated to be 0.339 pA/E. coli/mL (n=3) with a linearity factor (R2) of 0.999. These results showed that the on-chip chemiluminescent immunoassay for bacterial detection could be performed using passivation layer coated CdS NW photosensor. Keywords: CdS nanowire, Photosensor, Surface passivation, On-chip immunoassay 1 Department of Materials Sciences and Engineering, Yonsei University, 50 Yonsei-Ro, Seo-dae-mun-gu, Seoul 120-749, Korea 2 Korea Institute of Science and Technology (KIST), Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea *Correspondence and requests for materials should be addressed to J.C. Pyun ( [email protected])
Introduction Recently, a cadmium sulfide (CdS) nanowire (NW) photosensor was reported to be fabricated via an in situ synthesis method1-12. In this method, a CdS NW was grown directly on an interdigitated electrode (IDE) through the pulsed laser deposition by using Kr-F laser as shown in Figure 1(a)10-12. The in situsynthesized CdS NW photosensor was reported to have high sensitivity because of two reasons: (1) there is a high density of nanowires on the IDE electrodes and (2) the direct synthesis of NW on the electrodes improved the contact between the nanowires and the gold electrode. Usually, the NW grown on a metal surface of IDE is very fragile in structure. For the photosensor applications, a passivation layer must be made on the surface to enhance the physical and chemical stability. Especially, the surface of CdS NWs has been known to react with reactive gas like O2 in air. When CdS was oxidized by O2, the CdSO4 is formed, and this CdSO4 does not response to light. To prevent this oxidation reaction with O2, it has been reported that a parylene film coating
Data Loading...
